code: def stop_dask_client(client, cluster=None):
      """
      Shutdown/cleanup a client and possibly cluster object returned from
      start_dask_client(). This also stops the cugraph.dask.comms.comms
      singleton.
      """
      Comms.destroy()
      client.close()
      if cluster:
          cluster.close()
      # Remove a TemporaryDirectory object that may have been assigned to the
      # client, which should remove it and all the contents from disk.
      if hasattr(client, "tempdir_object"):
          del client.tempdir_object
      # FIXME: use proper logging, INFO or DEBUG level
      print("\nDask client closed.")
  
imports: import os
  import tempfile
  from pprint import pformat
  import time
  from dask.distributed import wait, default_client
  from dask import persist
  from dask.distributed import Client
  from dask.base import is_dask_collection
  from dask_cuda import LocalCUDACluster
  from dask_cuda.initialize import initialize
  from cugraph.dask.comms import comms
  from cugraph.dask.common.mg_utils import get_visible_devices
  from cugraph.generators import rmat
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: stop_dask_client(client, cluster) without return types